Automatic document feeders (ADF) are often included in printers, scanners, and multi-function devices for automatically loading and unloading single sheets of media, such as paper, sequentially to a functional station where the apparatus performs an operation (e.g., sequentially scanning the fed document sheets for copying, faxing, or displaying on a computer monitor). In an ADF system, detection of leading and trailing edges of the media feeding through it is used so that the system can know when to start and stop scanning. This is typically performed through at least one electronic sensor and a flag. Automatic document feeders typically utilize sensors for detecting the leading edge of a document as the document is withdrawn from an input or supply tray and fed into the scanner. From the point in time that the leading edge is detected, the amount of time to convey the leading edge to the imaging sensor is monitored so that the imaging sensor can initiate actual imaging (scanning) reader at the precise time when the leading edge of the document reaches the imaging reader. This amount of time will be more or less depending on the relative location of the sensor, or sensors, in the ADF document feed path.